How hummingbirds are inspiring military drones

A small military drone can fly as efficiently as most hummingbirds, but one still stands out ahead of the robot. Engineers may use those birds' wings to help create better drones.

Engineers often look to nature to design more efficient devices. The prickly heads of burdock plants gave rise to velcro, sharks' skin has inspired superfast Olympic swimsuits, and gecko feet may soon help soldiers scale walls.